Apparatus for winding glass strands

ABSTRACT

Motorized collet having a plurality of co-acting fingers and wedges which during rotation of the collet provide a smooth periphery for engagement with a forming tube is described. In a nonrotating state the fingers and wedges are constructed and arranged in such a manner that they retract from their engagement with each other. The angle is provided between the fingers and wedges in an expanded state is nonlocking and the fingers are provided with a central pin member or guiding rib to prevent any shifting tangentially of fingers from the rotating hub during operation.

United States Patent [191 Kallenborn Mar. 18, 1975 APPARATUS FOR WINDING GLASS STRANDS [75] Inventor: John Kallenborn, Murrysville, Pa. [73] Assignee: PPG Industries, Inc., Pittsburgh, Pa.

[22] Filed: Aug. 3, 1973 [21] Appl. No.: 385,361

[52] US. Cl. 242/18 G, 242/46.5 [51] Int. Cl B65h 54/44, B65h 74/24 [58] Field of Search 242/18 G, 46.2, 46.3, 46.4,

[56] References Cited UNITED STATES PATENTS 2,335,602 11/1943 Nash et al 242/72 2,703,685. 3/1955 Stephan 242/72 2,891,798 6/1959 Smith 242/18 G UX 2,906,470 /1959 Fletcher 242/18 G UX 3,195,821 7/1965 Woosey et a1. 242/18 G 3,544,016 12/1970 Cunningham et al 242/18 G 3,666,194 5/1972 Gosnell 242/72 FOREIGN PATENTS OR APPLICATIONS 843,668 8/1960 Great Britain 242/18 G Primary Examiner-Stanley N. Gilreath Attorney, Agent, or Firm-John E. Curley [57] ABSTRACT Motorized collet having a plurality of co-acting fingers and wedges which during rotation of the collet provide a smooth periphery for engagement with a forming tube is described. In a nonrotatlng state the fingers and wedges are constructed and arranged in such a manner that they retract from their engagement with each other. The angle is provided] between the fingers and wedges in an expanded state is nonlocking and the fingers are provided with a central pin member or guiding rib to prevent any shifting tangentially of fingers from the rotating hub during operation.

2 Claims, 4 Drawing Figures APPARATUS FOR WINDING GLASS STRANDS BACKGROUND OF THE INVENTION In the manufacture of continuous glass filaments, particularly in the winding of continuous glass filaments, it has been the practice of the art to wind continuous filaments onto a collapsible tube mounted on an appropriate mandrel.

High compression forces are developed during the winding of continuous glass filaments due to the inherent tensile strength of fibrous glass strand, its elastic elongation under tensile forces and the high speeds which are typically utilized in winding this type of strand. These compression forces developed in winding glass strand typically are greater than those encountered in winding other filaments of a synthetic or natural origin.

In a completely wound package of fibrous glass strands the accumulated high compression forces are such that the packaging tube on which the strand is wound is constricted by them. The constricting force makes it difficult to remove the packaging tube from the mandrel or collet. In addition the glass strands are often flattened out in the grooves created in the constricted tube and are not easily removed from the package in further processing of the strand such as in twisting and plying operations.

One approach to this problem has been the use of a resilient, plastic packaging tube with a specially constructed mandrel. This system is described in U.S. Pat. No. 2,891,798. This has not proved entirely satisfactory due to a tendency of the plastic tubes to rupture under buildup of internal stresses and the fact that repeated expansion and contraction cause them to become misshapen.

Two recent patents designed to improve on the plastic tube concept are U.S. Pat. No. 3,687,381 and U.S. Pat. No. 3,544,016. Both ofthese patents employ rotatable mandrels which are equipped with elongated fingers in close relationship to each other and which extend lengthwise of the mandrel. The fingers are provided with a central groove along their length permitting portions of the packaging tube to collapse and enter into these grooves to relieve the compressive forces developed in winding. Tapered edges at the sides of the fingers provide further grooves into which the packaging tube may collapse to further contribute to the relief of compression forces developed during Winding.

While all of these prior art processes are meritorious in that they help alleviate a condition, often other problems are introduced. Thus, the use of spaced apart fingers in a collet design creates longitudinal creases in the packaging tubes on which glass yarns are wound. Sharp, regular creasing of packaging tubes is undesirable since it often results'in damaged yarn due to the fact that operators tend to place the packaging tubes on the mandrels with the creases lined up in the spaces provided between the fingers.

THE PRESENT INVENTION ln accordance with the present invention a novel collet and motor assembly is provided for winding glass fiber strand on packaging tubes. Provision is made for the retraction of the smooth surface of the collet during doffing to insure ease of removal of the associated packaging tube from the collet surface.

Thus, the present invention involves a motorized collet design in which a smooth outer surface onto which a packaging tube may be placed is provided by alternating elongated fingers and wedges constructed and arranged so that during rotation essentially no gap is permitted between a finger and an associated wedge. The peripheral surface of the collet is then essentially smooth and unbroken. An angle is provided between the fingers and the wedges such that they are nonlocking, thus permitting the wedges and fingers to retract to a rest position when the collet is in a nonrotating state thereby reducing the diameter of the collet substantially. The fingers are provided with a central pin which slidably engages a channel positioned on the hub which is attached to the rotor of the motor associated with the winder to prevent any fingers from shifting tangentially from the collet during rotation.

The invention will be more readily understood by reference to the accompanying drawing in which FIG. 1 is a longitudinal section of the collet of FIG. 2 and taken along line 1-ll showing the internals including the motor,

FIG. 2 is a cross section of the collet of FIG. 1 taken along lines 22 with the motor unit removed to illustrate only the collet surface with the fingers and wedges shown in both an extended and a nonextended position,

FIG. 3 is a longitudinal section of the collet of FIG. 4 taken along lines 3-3 and depicting magnets utilized to assist in retraction of the collet fingers, and

FIG. 4 is a cross section of FIG. 3 taken along lines 4-4 with the motor removed to illustrate the fingers, wedges and magnetic retraction system of the inventron.

Turning to FIG. 1, there is shown a motor assembly having a stationary shaft 11, having a stator element 12 surrounding it. An air gap 13 is provided around the periphery ofthe stator 12 between it and a rotor 14 which is operatively associated with the stator 12. The windings 15 of the stator 12 are connected to a suitable power source not shown through electrical leads 19 which pass through shaft 11 via holes 20 and 21. Hub member 22 ismechanically connected to the rotor 14 through a mechanical lock and set screw, now shown, A bearing mounting 16 is provided at one end of the unit and is provided with a tapped bore hole 17 which is aligned with a similar tapped bore hole 18 located in a collar 23 provided on the interior of hub 22. A locking set screw 24 is provided in the bore holes 17 and 18 to firmly attached the bearing mounting 16 to the hub member 22. A sealed ball bearing 25 is positioned between the bearing mounting l6, lock nut 26 and end cap 27. End cap 27 is provided with a bore hole 28 through which a set screw 29 passes and threadedly engages a similar bore hole 30 provided for this purpose in the bearing mount 16.

At the end of the collet through which shaft 11 protrudes, a sealed ball bearing 31 is provided. This hearing 31 is mounted on shaft 11 between a back end cap 32 which also serves as a bearing mounting, thrust ring 33 and bearing cap 34. Bearing cap 34 is secured to the back end cap 32 through a set screw 35 which is positioned in a bore hole 36 in bearing cap 34 and a com municating bore hole 37 in back end cap 32. A bearing cap seal 56 is provided behind the bearing cap 34 around to shaft 11. Back end cap 32 is secured to hub 22 by bolt 61 which passes into a tapped bore hole 60 3 in hub 22 and through a similar bore hole 59 in end cap 32.

As shown in more detail in FIG. 2, hub 22 is provided on its periphery with a plurality of grooves and extension. Thus, as shown therein, each finger element 38 is provided with a slightly curved outer surface. The fingers 38 are provided on their undersurface with a central tongue member 39 and two side arms 40 and 41. Arms 40 and 41 are angled inwardly toward the tongue 39. Hub 22 is provided with slots 42 and tongue members 43. Slots 42 are constructed and arranged along the longitudinal axis of the hub 22 so that the tongue 39 of the finger element slidably engages the slot 42. On either side of the tongue 43 are channels 44 and 45. Between each of the slots 42 on either side thereof are located extensions 47 and 48 of the hub 22. A wedge member 46 provided with a central slot 49 on the underside thereof slidably engages the tongue 43 and frictionally engages the arms 40 and 41 of adjacent fingers.

When the fingers 38 and the wedges 46 have been placed around the hub member 22, the entire unit is then sealed shut by the locking end cap 58 which is conveniently bolted to the hub 22 through means of set screw or bolt 51 which passes into a tapped bore hole 52 in the hub through a similar hole 53 provided in the hub 22. A groove 55 is provided on the interior of end cap 58 which receives a ring or gasket (not shown) to hold a plate 54 in place against the end cap 58 and thereby closes the interior of the device to the atmosphere.

In FIG. 2, the left half of the figure shows the fingers 38 and wedges 46 in an extended position. This is the position these elements assume when the collet of the instant invention is rotating at winding speed. The right half of the drawing shows the position of the fingers 38 and wedges 46 when the collet is not rotating.

As can be readily appreciated, in their extended form the wedges 46 lock in place against the arms 41 and 40 of the finger elements 38 forming a smooth substantially unbroken peripheral surface on the collet. The tongue 43 is sufficiently long so it extends into the slot 49 a sufficient distance to prevent the removal of the wedge other than by sliding it off the collet in a longitudinal plane from the hub 22. Similarly the tongue 39 and slot 42 are proportioned such that in rotation or at rest fingers 38 cannot be removed except by sliding them off in a longitudinal plane from the end of the hub 22.

A critical, nonlocking angle 57 is provided to permit the wedges 46 and fingers 38 to retract as the rotation of the collet is diminished during a doffing operation. Thus, nonlocking angle-57, as shown, is formed at the intersection of a line drawn through the axis of a tongue 43 and a line extending the interface line between a side 40 or 41 of a finger 38 and the sides of a wedge member 46. The angle 57 shown is typically at least usually between 17 and 22 and preferably between 18 and In FIG. 3, a modification of the collet in FIG. 1 is shown which employs a plurality of magnets 65 to assist in retraction of the fingers 38 as collet rotation diminishes during shut down of a winding operation. Thus, as shown, therein the hub member 22 which is affixed to rotor 14 by a lock mechanism (not shown), is provided with a plurality of bored sockets 62. These sockets are constructed so that the pole 63 of a magnet 65 can be screwed into, or otherwise mounted in. the socket 62.

The underside of the fingers 38 are provided with slots into which there is placed an opposite pole 64 of the magnet 65. Poles 63 and 64 of the magnets 65 are positioned such that their faces are directly opposed to each other. The remaining parts of the collet shown in FIG. 3 are identical to FIG. I and reference to the description of them hereinabove in describing FIG. 1 may be made.

FIG. 4 is a cross section of the collet of FIG. 3 taken along lines 4-4 to show the positioning of the magnets 65 and the poles 63 and 64 thereof. The right hand side of the drawing shows the fingers 38, wedges 46 and magnets 65 as they appear when the collet is not rotating. The left hand side of the drawing shows the fingers 38, wedges 46 and magnets 65 as they appear during rotation.

It will be noted in both FIG. 1 and FIG. 2 that two rows of fingers 38 are provided end to end along the longitudinal axis of the collet. As will be appreciated by the skillled art, this will permit the winding of two packaging tubes on the collets shown in these drawings. In such an instance, a traverse mechanism for each side would be provided. The collet, of course, is equally suitable for winding a single packaging tube. In this instance, a smaller hub with a single row of fingers along the long axis of the collet will suffice and a single traverse to reciprocate the strand back and forth longitudinally on the surface of the packaging tube is utilized.

The packaging tube placed on the collet of the instant invention may be conveniently constructed of paper or other similar fibrous material which exhibits some tendency to wrinkle under compression. Any of the conventional forming packing tubes constructed of paper now available are suitable for this use.

In a typical embodiment of the invention a collet was constructed as shown in FIG. 1 and associated with a source of molten glass. The molten glass source was an electrically heated platinum bushing having 1,000 ori fices therein. The 1,000 glass fiber filaments which were D 1 50s emanating from this bushing were split mechanically into two groups, each group containing 500 filaments. .The two groups of filaments, after application of a forming size were gathered into two separate strands, each containing 500 filaments.

The collet associated with the bushing was 28 inches in length and contained two fingers 38, each 14 inches in length, in the longitudinal plane. A plurality of rows of fingers were located around the periphery of the collet. Between each row of fingers were locaated two wedges 46 arranged end to end in a longitudinal plane on the collet and in rows around the periphery of the collet to provide a wedge 46 between each finger 38 on the periphery of the collet. In a nonrotating state, the outside diameter of the collet was 11 /8 inches. Two paper packaging tubes having internal diameters of 12 inches were placed on the collet. Each tube has a traverse mechanism associated with it to reciprocate the strand back and forth in a longitudinal plane onto the packaging tube surface.

The two strands from the bushing are secured to each of the packaging tubes through their associated traverse mechanism. The motor of the collet which had 7 /2 horsepower rating was turned on and rotated at about 6,600 revolutions per minute. This produced a winding speed on the periphery of the collet of 16,000 feet per minute. The nonlocking angle 57 was 20 in this collet and during rotation the outside diameter of the collet was twelve and one quarter 12% inches. The collet was rotated until the glass strand wound on each packaging tube amounted to thirty eight pounds. The collet was then stopped and the packaging tubes containing the glass strand were removed by hand with ease.

It has been observed that after a long period of standing, the packaging tubes tend to wrinkle internally usually in a single longitudinal crease. When utilized again, the crease is ironed out by the rotation of the collet. When collets are utilized containing the magnetic retraction assistance system of FIG. 3, it is found that the packaging tubes are even easier to remove from the collet surface after use since all the fingers are completely retracted around the periphery of the collet.

Collets constructed in accordance with this invention have been found suitable for winding fibers of various diameters. Thus, the D fibers of the example DE, C, G fibers, and others may be wound using this collet.

In the construction of the winding device of the instant invention, normal construction materials such as steel, aluminum, nickel and the like may be employed. It is preferred that the fingers 38, wedges 46 and hub 22 be constructed of aluminum to reduce the weight of the nuit and provide corrosion resistance since these surfaces are exposed to considerable chemical binder and size solutions used in processing glass strand. The stationary shaft ll of the motor assembly of the collet is found advantageous in the winder of this invention since it is not subject to critical speeds and prevents any high vibration of the device at high speeds of rotation. This is advantageous in winding glass strand since it reduces the variations in strand denier (diameter) that might otherwise be encountered. Depending on motor size, collet diameters and the like winding speeds on the collet periphery are generally 10,000 to 18,000 feet per minute or more. Typically, these winding speeds are 12,000 to 16,000 feet per minute.

While the invention has been described with neglect to certain illustrated embodiments, it is not intended that it be limited thereby except insofar as appears in the accompanying claims.

I claim:

ll. An apparatus for winding strand onto a forming package comprising in combination a motor having a centrally disposed statinary shaft; a stator mounted on said shaft; a rotor circumferentially disposed around said stator; a hub member secured to the outer circumference of said rotor and rotatable therewith; a plurality of channels and slots positioned along the long axis of said hub member on the exterior surface thereof; a plurality of longitudinal elongated fingers and wedge members received in said channels each of said fingers being characterized by having sloping side portions and a centrally disposed tongue member slideably engaging a respective one of said slots longitudinal tongue members positioned along the long axis of the hub and engaging a slot in respective wedge members; the side portions of said fingers and the vertical axis of said tongue members on said hub forming a nonlocking angle between the Wedge members and the fingers member associated therewith, said fingers and said wedge members being characterized by being movable in an axial direction when the motor is actuated by centrigugal force until they lock by engagement with the side portions of each to form a smooth unbroken peripheral surface and being freely retractable when at gers against said hub. 

1. An apparatus for winding strand onto a forming package comprising in combination a motor having a centrally disposed statinary shaft; a stator mounted on said shaft; a rotor circumferentially disposed around said stator; a hub member secured to the outer circumference of said rotor and rotatable therewith; a plurality of channels and slots positioned along the long axis of said hub member on the exterior surface thereof; a plurality of longitudinal elongated fingers and wedge members received in said channels each of said fingers being characterized by having sloping side portions and a centrally disposed tongue member slideably engaging a respective one of said slots longitudinal tongue members positioned along the long axis of the hub and engaging a slot in respective wedge members; the side portions of said fingers and the vertical axis of said tongue members on said hub forming a nonlocking angle between the wedge members and the fingers member associated therewith, said fingers and said wedge members being characterized by being movable in an axial direction when the motor is actuated by centrigugal force until they lock by engagement with the side portions of each to form a smooth unbroken peripheral surface and being freely retractable when at rest by gravitational forces.
 2. The apparatus of claim 1 including magnetic means on said hub and said fingers for holding the fingers against said hub. 